Rick, I had to do this for XP 32bit machines, over 40 so far worked well.

I believe I have seen scripts to help work with or disable UAC.  But check to see if that registry exists as other scripts I checked on this board didnt work for me.

To get around UAC, you need to run as SYSTEM and not the user.

To dissable UAC on windows 7 run this step in a procedure:

Set Registry Value

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA

change value to 0

the data type is REG_DWORD

*****This does not take affect until the computer is rebooted******

After a bit of testing, I wanted to follow-up with some of my gripes about SEPprep:

1. The reboots are not configurable. In other words, the application will reboot without asking (in unattended mode).

2. SEPprep is basically a universal uninstaller. However, if your uninstalls were failing due to a corrupt uninstaller, they will still fail with SEPprep.

3. There is a way to configure different uninstall switches, but not per product. It only gives you one line to set custom switches.

for the reboot: that is configurable. Its one of the things in the .ini file. Did you download the SEPprep manual? it outlines how to use the tool